Victor Reppert on the Argument from Evil as a Reductio

Can atheist who rejects moral realism press the argument from evil? Many theists, including William Lane Craig and Ravi Zacharias, have argued that the answer is “no.” In my old critique of one of Zacharias’s books, I wrote the following.

Zacharias presents two objections to AE. First, he suggests that it is incoherent for atheists to appeal to evil as evidence of the nonexistence of God since objective moral evil could not exist if there is no God (p. 48). Yet, as I argued above, objective moral values are logically possible even if there is no God. And the atheist need not postulate the existence of objective moral values in order to use evil as evidence for atheism. An argument from evil might not contain any normative premises; the atheist could appeal to God’s loving nature rather than God’s moral nature.[13] For example:

(1) If a perfectly loving God were to exist, then he would not permit the occurrence of any unjustifiable suffering. (2) But unjustifiable suffering does occur. (3) Therefore, a perfectly loving God does not exist.

To emphasize the point (though I consider this unnecessary), the atheist might even change the name of the argument from “the Argument from Evil” to “the Argument from Unjustifiable Suffering.”[14]Most importantly, AE may be understood as a challenge to the internal coherence of a theistic worldview. An AE can be understood as saying something like the following:

Look. You theists believe that X, Y, and Z are evil. You theists believe that God is good. You theists believe that good persons are opposed to evil. So you theists need to explain why a god who is good (in your sense of ‘good’) would allow so much apparently pointless evil (in your sense of ‘evil’). If you can’t explain it, then that is a problem for the internal coherence of your worldview.[15]

When AE is understood in this way, it doesn’t presuppose that there are objective moral values.

In an old post, Victor Reppert says that he is aware of running the argument from evil as a reductio ad absurdum argument, but he is unconvinced. He writes:

I still maintain that important phenomena that give rise to the problem of evil are themselves deeply problematic for naturalism, including consciousness, objective moral values (and yes I know all about running it as a reductio without presupposing objective moral values–I still think subjectivism undercuts the argument).

Here’s my question to Reppert: why? How does subjectivism undercut the argument? For example, how does subjectivism undercut Draper’s version of the evidential argument from evil (summarized here)?